code: def _85encode(
      b, chars, chars2, pad=False, foldnuls=False, foldspaces=False
  ):
      # Helper function for a85encode and b85encode
      if not isinstance(b, bytes_types):
          b = memoryview(b).tobytes()
  
      padding = (-len(b)) % 4
      if padding:
          b = b + b"\0" * padding
      words = struct.Struct("!%dI" % (len(b) // 4)).unpack(b)
  
      chunks = [
          b"z"
          if foldnuls and not word
          else b"y"
          if foldspaces and word == 0x20202020
          else (
              chars2[word // 614125]
              + chars2[word // 85 % 7225]
              + chars[word % 85]
          )
          for word in words
      ]
  
      if padding and not pad:
          if chunks[-1] == b"z":
              chunks[-1] = chars[0] * 5
          chunks[-1] = chunks[-1][:-padding]
  
      return b"".join(chunks)
  
imports: import re
  import struct
  import binascii
label_desc: Use image node_id 16 for calling a global function with example usage: _85encode(b, chars, chars2, pad, foldnuls, foldspaces) and returns: bytes